1. Field of the Invention
The present invention relates to apparatus and methods for identifying product performance faults. More specifically, the present invention relates to apparatus and methods for identifying and resolving device performance faults in printers, copiers and other media processing apparatus.
2. Description of the Related Art
Many products are assembled from a complex array of components that interact mechanically and electrically to accomplish one or more functions. Frequently, the individual functions are further subdivided into a plurality of sub-functions or cycles. Naturally, a complex product may be subject to defects in materials and workmanship, normal wear, degradation, improper service, abuse, and consumption such that peak design performance cannot usually be maintained over the life of the product. All these factors contribute to general product degradation over time, which can occur gradually or suddenly. However, degradation does not necessarily imply total failure of the product, as the effects of degradation frequently manifest themselves as gradually reduced product performance, increased noise, changes in appearance and sound, increased consumption and so forth. It is common for a user to notice the degradation, in fact such notice is frequently an indicator to a user that there is a present need to service a product.
When a user has noticed one or more events related to the performance of a product that are indicative of reduced product performance, such information can be used in an attempt to isolate and resolve the problem. For example, the user may refer to an owner/operator manual's troubleshooting section to locate a table of symptoms, causes and effects to identify the problem at the root of a given set of symptoms. Similarly, the user may contact a service provider to request service for the product and at the same time relay to the service provider the events or symptoms that indicate to the user that service is needed. In fact, the nature of the events that are indicative of a need for service, are similarly useful to identify a particular problem and point to an appropriate service requirement.
An example of a product that fits the foregoing model is the computer laser printer. While there are a great range of sizes, capacities and features respecting laser printers, they are all similar in that each is a complex electromechanical device. Laser printers generally include paper feed trays, paper feed and registration mechanisms, image drums, developers, transfer belts, fusers, paper output feed mechanisms, collators, output paper trays and many other components. Motor driven belts and rollers are typically used to move paper through the printing process. Frequently, gears are used to maintain alignment and timing of rollers. Springs are employed to maintain pressure and alignment of components. A variety of sensors are usually disposed within a laser printer to establish the location and control the timing of movement of the paper as it passes through the printer. Some sensors are provided for the purpose of detecting faults, such as jams and some are used to detect and report consumable levels, track page counts and et cetera. While laser printers are generally designed for quiet operation, a certain level of mechanical sound is currently unavoidable in operation of a laser printer.
As components wear, are consumed, or otherwise degrade in performance, the sounds and characteristics of the laser printer change. For example, a clunking sound may develop. A repetitive squeaking sound may develop or perhaps a rubbing or scratching sound. Perhaps a visual queue will develop, such as the paper beginning to pull out of alignment at a particular time in the printing cycle. The paper jamming in the same place during each printing or collating cycle is another example. A trouble indicator lamp on the printer may illuminate at a particular time during the printing cycle. These are the kinds of events that lead a user to question the performance of the product. These are also the kinds of indications that are useful in troubleshooting the product, either by the user or by service personnel.
Some of the aforementioned events indicative of degradation in performance are intermittent. Intermittent events indicative of degradation are problematic from a service point of view. A user may place a call for service and the service personnel may make a site visit to effect the needed repair, only to find that the symptom has vanished during the time it took to arrive on the service call. This may be frustrating and costly as the service technician is often unable to duplicate the symptom. Consequently, service may require more time or a second service call at a later date.
Those trained in repair of laser printers or other electromechanical devices appreciate the value of experiencing first hand and considering the aforementioned events indicative of degradation in performance while attempting diagnosis and service of a device. These individuals often value the subtle information that is present when the event characteristics are considered in view of the product itself. For example, a sound that occurs each instance that a new sheet of paper is fed into the printer is more likely to indicate a problem in the input feed mechanism than it is in the output feed subsystem. Similarly, a repetitive sound that occurs much more frequently than the image drum operating cycle period is not likely to result from the operation of the image drum. It would more likely result from a faster operating transfer roller, such as one that has an operation cycle of equal duration. Whether a certain function of the printer is enabled or not, such as a page duplexer or a collating feeder, is useful in determining whether or not that portion of the device ought to be studied in the fault investigation process. Device faults can be isolated by the time events occur, the frequency with which they occur, whether a particular function is presently enabled, as well as other timing related events.
Thus there is a need in the art for an apparatus and/or method for gathering and analyzing event information indicative of degradation in performance of a product.